Typical space launch systems include multiple vehicles that are attached together and perform differing functions in delivering/retrieving a payload (either cargo and/or a crew) to and from orbit. For example, the space shuttle system operated by the National Aeronautics and Space Administration is comprised of four vehicles: (1) an orbiter (commonly referred to as the space shuttle) with three (3) main propulsion engines; (2) an external tank; and (3) two (2) solid rocket boosters. The boosters are attached to the external tank which is attached to the orbiter. The boosters are solid propellant motors that provide initial ascent propulsion (along with the main engines) for about two minutes of flight then separate from the external tank (and orbiter) and descend by parachute into the Atlantic Ocean. The boosters are recovered by ship, returned to land, and refurbished for reuse. The external tank provides liquid oxygen and liquid hydrogen to the main engines on the orbiter during initial ascent and separates from the space shuttle system prior to reaching orbit. The external tank destructively returns to earth independently of the orbiter. The orbiter, using the main engines and an onboard propellant supply, continues to propel itself into orbit where it delivers/retrieves a payload. The orbiter after completing its task(s) non-destructively returns to earth and glides to a horizontal landing at a designated landing site. The orbiter is then refurbished for reuse in another space launch.
Each of the various vehicles that comprise a space launch system requires extensive engineering and testing to ensure that the vehicle and the various components that make up that vehicle can safely perform their intended functions. Prior art space launch systems have designed each the vehicles significantly differently. Each of the different designs requires individual analysis of each of the components (engines, fuel/oxidant supplies, aerodynamics, avionics packages, landing gear, life support, etc.) that comprise each of the vehicles. Designing, analyzing, developing, testing, etc. of each the different designs and components requires large expenditures of money and time. Additionally, because of the differences in the vehicles and the components, personnel that operate and maintain these vehicles require extensive training for each of the individual vehicles and components. Thus, the different designs increase the cost and complexity of the space launch system.
Accordingly, it is desirable for the various vehicles that comprise the space launch system to share some common components, features or parts and/or vehicle design so that the time and cost to develop, maintain and operate the various vehicles and the space launch system is reduced. That is, having commonality between the various vehicles in a space launch system enables common aspects or components of the vehicles to be designed, developed, tested, and built with less labor hours and less cost. Additionally, the cost to operate, inspect and maintain these common components will also be reduced because personnel trained to operate, inspect and maintain the components in one vehicle can also be used to operate, inspect and maintain the common components in different vehicles. Thus, commonality between the vehicles can reduce the cost to design, build, operate and maintain a space launch system.
In addition to the use of common components in the various vehicles that comprise a space launch system, cost savings can also be obtained by using all reusable vehicles in the space launch system. That is, typical space launch systems include vehicles that are destroyed during the space launch operation or require expensive retrieval (water landing vehicles). The destructive use of these vehicles in a space launch system requires these vehicles to be replaced each time a new space launch is to be performed. If the vehicles used in the space launch system can be reused, the cost to supply new vehicles each time a space launch is to be performed can be avoided. Additionally, if the reusable vehicles return to earth and land at a designated land based area, the cost of ocean retrieval can be avoided thus further reducing the cost of operating the space launch system. Accordingly, it is desirable to provide a space launch system that uses reusable vehicles that return to earth and land at a designated land based area.